With the fast growing of the electric technology development, all kinds of electric products may be based on consumer demand. A slim volume is a must for electronic devices as camera, cell phone, notebook, LED molds, PDA, etc. And it is the point for designing such electronic products.
Since those small electronic devices being smaller, continuously the components as FPC, circuit, display, panel, connector, and the related are gradually smaller as well. There are some cables or flexible FPCs existed among such components mentioned above.
It is to be noted that the flexible FPC features a light weight and a thin volume. When the flexible FPC is fabricated on the panel or tested, the flexible FPC is often inserted in and pulled out from troughs, the circuits of the front end of the FPC are easily caused broken, and the appearance is damaged as well. So, the defect rate is increased.
A general flexible FPC as shown in FIG. 1, which is a schematic lateral view of the flexible FPC in prior arts. The FPC comprises a base board 10, a copper 101, and a cover layer 103. The base board 10 of the flexible FPC is thinner to deflection arbitrarily, and the base board 10 is usually made of PI with yellow-brown color and PET with colorless. There is a copper layer 101 rolled on a surface of the base board 10. The copper layer 101 is etched to form circuit patterns needed by means of chemicals with soul or alkali and light etching procedures. Continuously other procedures as mechanical machining, fabrication, etc. may be processed to mounted components on the base board 10 so as to form the flexible FPC.
Between the base board 10 and copper layer 101 usually needs to add an adhesive 102 for bonding. For the whole thickness of the flexible FPC meeting needs, the thickness of the base board 10 and the adhesive 102 is usually under 0.1 mm. The adhesive 102 is made of epoxy resin or acrylic fiber.
For avoiding the surface of the copper layer 101 of the base board 10 being damaged or contaminated, one more cover layer 103 is coated on the surface of the copper layer 101. The cover layer 103 is a film and has the same material with the base board 10 for protecting the circuits of the copper layer 101.
Referring to the FIG. 2, which is schematic view of the flexible FPC connecting another connecter in prior arts. The flexible FPC 1 can be through a front end of the connector 105 to connect other FPCs or troughs 104 of other lines. Since an endpoint in the trough is formed by means of electroplate tin or lead-tin, and the connector 105 of the flexible FPC 1 is plated with tin of 5˜15 μm, which is called “Golden finger”. By means of connecting the connector 105 and the trough 104, therefore the flexible FPC is electrically connected other FPCs.
According to mentioned above, with electronic products sizes being gradually smaller, the flexible FPC fabricated in the electronic products shall be thinner than ever to connect different electronic components in a limited space. It is to be noted, the base board of the flexible FPC is comparatively skinny, therefore it is easily deformed while applying a force. Hence, the base board is hardly conveyed by automation. So the tests or fabrication must be manually handled.
While a user inserting in and pull out from the FPC and the connector causes stress focused on the front end of the FPC, particularly, the connector located on the front end and constructed by the “Golden finger” is relatively heavier than the whole FPC. So the contacting lines of the front end are easily occurred broken circuits and damaged the flexible FPC while inserting in and pulling out the FPC from the troughs. It is then that the defect rate is higher than 2.17%.
Further more, in the aspect of testing the appearance of the FPC, the base board is often manually touched so as to scratch the surface or damage the appearance while manually inserting in and pulling out the FPC. Therefore, the defect rate is up to 30%. As a conclusion, how to solve the drawbacks of the broken circuits and the damaged appearance is an important issue in the field.